This invention broadly relates to a semiconductor device and a method of manufacturing the same.
More specifically, this invention is directed to a mounting structure of a power device.
In a conventional package of a power device, a semiconductor device such as a power device is generally provided by the use of a lead frame, and is resin-sealed by the known transfer molding method.
Referring to FIGS. 1A and 1B, description will be made about a method of mounting the power device disclosed in Japanese Unexamined Patent Publication (JP-A) No. Hei. 6-37122.
Before assembling the semiconductor device, a lead frame having a header (die pad) 21 and a lead 23 linked by a dam (tie bar) 26 is formed by punching a metal plate.
With this structure, a groove 28 is formed directly under a pellet-outer periphery portion of a pellet-attachment portion of an upper surface of the header 21.
As illustrated in FIG. 1A, the pellet 22 is attached on the header 21 by solder 25. Further, a wire 24 is connected between an electrode on the pellet 22 and the lead 23.
Subsequently, the lead frame provided with the pellet 22 is arranged in a sealing die, and is resin-sealed such that sealing resin 27 exposes the back surface of the header 21 and covers the upper surface thereof. After sealing the resin, each lead 23 is separated by cutting the dam 26.
In the above-mentioned mounting method, the lead frames are designed to different shapes in the case where the kinds of the devices are different to each other. Consequently, manufacturing equipments are fixed at every kinds, and a production line is not flexible.
Further, a specific lead frame die for forming a metal lead frame must be prepared at every kinds. These facts cause cost-up. Moreover, the number of the devices, which are made once from the lead frame, is reduced so as to lower production efficiency.
In consequent, it is difficult to cheaply provide the package for the power device in the conventional method.
It is therefore an object of this invention to provide a semiconductor device having a small-sized and cheap mounting structure.
In a semiconductor device according to this invention, an insulating substrate has a plurality of through holes.
A plurality of conductive posts are buried in the through-holes. In this case, the conductive posts are classified to at least one first conductive post and a pair of second conductive posts.
Further, a semiconductor element has at least one surface electrode at a surface side. Herein, the surface electrode is connected to the first conductive post by a face-down method.
Moreover, a metal block is formed to a square-arch shape in a cross sectional view and has a ceiling portion and both end portions. In this event, a back surface of the semiconductor element is secured to the ceiling portion while the both end portions are secured to the second conductive posts.
In addition, a sealing-resin seals the semiconductor element.
With this structure, the semiconductor element has a back surface electrode at a back surface side. The back surface electrode is connected to the second conductive posts via the metal block.
In this case, each of the first and second the conductive posts may be formed by the use of Cu paste.
Further, a first substrate electrode is formed on the first conductive post. The surface electrode is connected to the first conductive post via the first substrate electrode.
Herein, the first substrate electrode may be formed by the use of Ag paste.
Moreover, a second substrate electrode is formed on the second conductive post. The metal block is connected to the second conductive post via the second substrate electrode.
Herein, the second substrate electrode may be formed by the use of Ag paste.
In this case, the surface electrode comprises a bump electrode. The insulating substrate comprises a resin substrate.
Specifically, use is made of the insulating substrate such as the resin lamination plate. Further, the back surface electrode of the semiconductor device is drawn out into the side of the insulating substrate via the metal block which commonly serves as the heat sink. The semiconductor substrate is entirely resin-sealed, and is cut to the individual parts by the use of the dicer.
In consequence, the power device can be manufactured in the production line having high flexibility irrespective of the kinds of the equipments.
Further, the small-sized power device having high heat-dissipation characteristics can be realized in the mounting structure.
More specifically, the pellet is arranged on the insulating substrate having the conductive post by the use of the face-down method. Further, the metal block covers thereon such that the back surface electrode of the pellet can be drawn out to the conductive post.
After a plurality of pellets are entirely resin-sealed, the pellet is cut to the individual parts by the use of the dicer.
Consequently, the expensive manufacturing equipment is unnecessary. Further, it is possible to manufacture the semiconductor device in the production line having high flexibility and to effectively manufacture the semiconductor device.
Moreover, it is possible to cheaply provide the small-sized package having the high heat-dissipation characteristics without using the lead frame.